From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B8EEC4363D for ; Tue, 22 Sep 2020 14:39:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 20636239D2 for ; Tue, 22 Sep 2020 14:39:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20636239D2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B415E90009F; Tue, 22 Sep 2020 10:39:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ACB3A90009E; Tue, 22 Sep 2020 10:39:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9B93E90009F; Tue, 22 Sep 2020 10:39:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0028.hostedemail.com [216.40.44.28]) by kanga.kvack.org (Postfix) with ESMTP id 811BD90009E for ; Tue, 22 Sep 2020 10:39:10 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3BE498249980 for ; Tue, 22 Sep 2020 14:39:10 +0000 (UTC) X-FDA: 77290954860.10.tiger92_47073822714e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id 0E99016A0D1 for ; Tue, 22 Sep 2020 14:39:10 +0000 (UTC) X-HE-Tag: tiger92_47073822714e X-Filterd-Recvd-Size: 2015 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Tue, 22 Sep 2020 14:39:09 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id CD86767373; Tue, 22 Sep 2020 16:39:06 +0200 (CEST) Date: Tue, 22 Sep 2020 16:39:06 +0200 From: Christoph Hellwig To: Matthew Wilcox Cc: Christoph Hellwig , Andrew Morton , Peter Zijlstra , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Minchan Kim , Nitin Gupta , x86@kernel.org, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: Re: [PATCH 3/6] drm/i915: use vmap in shmem_pin_map Message-ID: <20200922143906.GB26664@lst.de> References: <20200918163724.2511-1-hch@lst.de> <20200918163724.2511-4-hch@lst.de> <20200921191157.GX32101@casper.infradead.org> <20200922062249.GA30831@lst.de> <20200922112144.GB32101@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200922112144.GB32101@casper.infradead.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Sep 22, 2020 at 12:21:44PM +0100, Matthew Wilcox wrote: > Actually, vfree() will work today; I cc'd you on a documentation update > to make it clear that this is permitted. vfree calls __free_pages, the i915 and a lot of other code calls put_page. They are mostly the same, but not quite and everytime I look into that mess I'm more confused than before. Can someone in the know write sensible documentation on when to use __free_page(s) vs put_page?